Vascular Diseases of Lungs
Pulmonary Hypertension
It is the increase in blood pressure in pulmonary arteries, veins and capillaries .
It leads to shortness of breath, dizziness and faintingM:F ratio 1:3Prevalence 15/million
Primary vs secondary
Presentation
Gradual onset of dyspnea and fatigue
Non productive cough
Syncope
Peripheral edema (ankle swelling)
PathogenesisArterial: vasoconstriction due to vascular hyper-reactivity due to endothelial dysfunction (low PG, NO, high endothelin)– thickening and fibrosis of blood vessels – increase pulmonary arterial pressure – increase work load to the right side of the heart – right ventricular hypertrophy – RV failure – less blood to the left side of heart – hypoxemia – systemic congestion of blood (liver, lower ankle swelling, increased jugular veinous pressure)
PathogenesisVenous: no obstruction of blood flow – Due to left side heart failure – pooling and congestion of blood in lungs – increase hydrostatic pressure in pulmonary veins – chronic process – pulmonary hypertension
Pathogenesis
Capillary: due to lung disease eg. idiopathic pulmonary fibrosis.
There is generalized fibrosis of the alveolar walls – changes of the capillary network due to loss and fibrosis – arterialization of capillaries – increase resistance and pressue
Generalized hypoxia - vasoconstriction
CausesWHO group I: pulmonary arterial hypertension: disease of arteries, idiopathic pulmonary arterial hypertension, vasculitis, autoimmune diseaseWHO group II: Pulmonary hypertension associated with heart diseaseWHO group III: Pulmonary hypertension associated with lung disease: COPD, interstitial pneumonia..
WHO group IV: Pulmonary hypertension due to multiple pulmonary thromboembolismWHO group V: Miscellaneous: others eg. Sarcoidosis
Diagnosis
Dyspnea, syncope
Elevated jugular venous pressue
Congested liver
Ankle edema
Clubbing of fingers
High pulmonary arterial pressure
Pulmonary Thromboembolism
Common clinical problem
Can be fatal
Frequently missed
Difficult to diagnose
95% thromboembolism of DVT (popliteal veins and larger veins of lower limb)
Predisposing factors for thrombosis
Risk factors:
Prolonged bed rest, following major surgery, severe trauma, congestive heart failure, contraceptive pills, cancer
Presentation
60-80% are asymptomatic
5% cause sudden death
10-15% cause lung infarction, presenting as sudden dyspnea, severe chest pain
3% are multiple and cause pulmonary hypertension
Consequences of pulmonary thromboembolism:
1 .Fatal if it is large (Saddle embolus)
2 .Infarction :
small emboli, distal occlusion of pulmonary arteries, can be multiple, wedge shape, hemorrhagic “red” infarct
3 .Pulmonary hypertension: multiple, chronic
4 .Cor pulmonale